TRAINING AND SUPERVISION OF TEMPORARY TRANSVENOUS PACEMAKER INSERTION

SUMMARY To assess the current training and practice of central venous cannulation and temporary transvenous pacemaker insertion, a telephone survey of senior house officers (n=60) and registrars (n=20) was carried out in 80 acute hospitals in England and Wales. A median of one central line and two pacings were performed under supervision before the respondents were left unsupervised. The procedures were almost invariably taught at the bedside and usually by a fellow SHO or registrar. Virtually all the doctors surveyed were familiar with subclavian puncture, but experience with other routes was limited; 39/80 doctors questioned were unhappy about the training they had received, and 47 felt that formal training, such as tutorials or videos, would have helped. Training in central vein cannulation and temporary pacing needs to be more structured. This could be done by the use of videos or mannequins, and should include the use of routes other than the subclavian.     

Agonist desensitisation of α1 adrenoceptors and endothelin-1 receptors coupled to phosphatidylinositol metabolism

Summary— Agonist desensitisation of responses coupled to phosphatidylinositol metabolism were studied. Responses mediated by two different agonists, endothelin-1 and noradrenaline were investigated. In vivo pressor responses were examined in conscious male New Zealand white rabbits, while effects on inositol phosphate formation were studied in rings of freshly isolated aorta and in cultured aortic vascular smooth muscle cells. No desensitisation of responses to noradrenaline were observed in vivo despite a 10-day infusion under conditions which cause desensitisation of α₂ and β-adrenoceptor mediated responses. In contrast, responses to endothelin-1 were attenuated within 5 min of commencing endothelin-1 infusions. No reduction in noradrenaline stimulated inositol phosphate was observed in cultured vascular smooth muscle cells after pre-incubation with noradrenaline up to 10⁻⁴M, whereas with endothelin-1 pre-incubation a dose and time-related reduction in endothelin-1 stimulated inositol phosphate formation was observed. Thus, differences in the pattern of desensitisation of both pressor responses and phosphatidylinositol metabolism were observed for noradrenaline and endothelin-1 suggesting that the nature of the 2nd messenger involved in signal transduction is not the only determinant of agonist desensitisation. In addition, differences in the rate of desensitisation and sensitivity to endothelin-1, but not noradrenaline, were observed when responses in cultured cells were compared with in vivo responses or responses to freshly isolated tissues. These differences are discussed in relation to possible modifications of the endothelin receptor or its coupling to phosphatidylinositol metabolism during culture.     

Ocular melanoma: total dose and dose rate effects with Co-60 plaque therapy

From 1968 to 1987, 123 consecutive patients with nonmetastatic choroidal melanoma were treated with cobalt-60 plaques. One hundred sixteen patients were followed up for a mean of 3.8 years. Twenty patients had local failure, and 14 patients had distant failure. Complications included 32 cataracts, and seven enucleations were required. Local recurrence did not correlate with tumor height, tumor volume, dose, or dose rate. Increased volume (P = .004) and height (P = .01) correlated with increased rates of distant metastases. Dose adjusted for volume did not correlate with the rate of metastases.     

Epidemiologic comparison of human T-lymphotropic virus type I-infected blood donors from endemic and nonendemic regions over a 3-year period

BACKGROUND: Screening for human T-lymphotropic virus type I (HTLV-I) infection became systematic in 1989 in the French West Indies for blood from all donors and in France for blood from natives of endemic areas; in 1990, it was extended to blood from donors with at-risk sex partners and in July 1991 to blood from all donors. STUDY DESIGN AND METHODS: The epidemiologic characteristics of individuals found through the screening of donated blood to be HTLV-I infected were compared for an endemic region (Guadeloupe, French West Indies) and a nonendemic region (Paris area) over a 3-year period (1989 through 1991). RESULTS: In Guadeloupe, 131 HTLV-I-infected individuals were detected in the screening of 28,801 units; in the Paris area, 38 HTLV-I-infected donors were detected in the screening of 109,824 units. All Guadeloupean HTLV- I-infected donors were natives of endemic areas. Among the 38 Parisian HTLV-I-infected donors, 21 were natives of endemic areas, 10 were natives of endemic areas and had received transfusions, 2 were whites who had received transfusions, and 5 were whites who had had heterosexual contact with natives of endemic areas. The percentage of HTLV-I-infected individuals whose blood would have been excluded because of positivity for one or more markers for other viruses did not significantly change over the study period and did not significantly differ between regions (41%). Among the eight Parisian HTLV-I-infected blood donors detected after July 1991, six would not have been detected without the biologic screening. CONCLUSION: The generalization of biologic screening of HTLV-I-infected donated blood in France was useful for the prevention of HTLV-I and HTLV type II infections through transfusion.     

Hepatitis C virus genotypes in a cohort of Australian blood donors and haemophiliac and liver transplant patients

The aim of the present study was to characterize hepatitis C virus (HCV) genotypes using the INNO-LiPA HCV line probe assay and direct sequencing from three different HCV-RNA-positive (serum) groups: (i) blood donors (n= 59); (ii) haemophiliacs (n= 43); and (iii) patients undergoing liver transplantation (n= 26). Of 128 HCV-RNA-positive samples, 74 (58%) were genotype 1. Of these, 41 were genotype 1a, 32 were genotype 1b and one was genotype 1 indeterminate. Of the remaining 54 samples, seven (5%) were genotype 2a, two (2%) were genotype 2b, 26 (20%) were genotype 3a, three (2%) were genotype 4a, while 16 (12.5%) were of a mixed genotype. There was no significant difference between the three groups with regard to the prevalence of any specific genotype. However, in blood donors and haemophiliac patients there was a statistically significant difference in the occurrence of genotype 3a in patients with elevated alanine aminotransferase (ALT) levels (30.3%) compared with those patients with persistently normal ALT levels (5.6%; P= 0.004; x²) Genotype 3a was also uncommon in liver transplant patients (one of 14) with ‘sporadic’ HCV infection. Genotype 4a was detected only in liver transplant patients. These patients had originated from Egypt (n= 1), Italy (n= 1) and Romania (n= 1).     

High frequency ventilation

The 1990s have seen a dramatic resurgence of interest in high frequency ventilation (HFV). The role of HFV in the rescue of infants failing conventional mechanical ventilation (CMV) is now relatively well established. However, the wider role of HFV in the routine management of respiratory failure in the newborn is more contentious. Recent trials in small numbers of infants suggest that HFV may be associated with significantly less chronic lung disease than CMV when used under optimal conditions (i.e. with a 'high-volume' strategy, from early in the disease and continued to the point of weaning). Further, clinical trials are now required to define the role of HFV more clearly.